This invention relates generally to agricultural machines and, in particular, to a swivel hitch for connecting an implement to a tractor.
U.S. Pat. No. 4,525,987 to Werner et al discloses a swivel hitch including an upper gearbox coupled to an input shaft on an implement and a lower gearbox connected to a power-take-off shaft on a tractor. In order to achieve the desired maneuverability of the implement during operation, the lower gearbox rotates relative to the upper gearbox about a generally vertical axis when the tractor makes turns. A drawback of the Werner et al swivel hitch is that the upper and lower gearboxes are linked to the implement and the tractor, respectively, in a manner such that the draft load applied to the tractor by the implement is transmitted through the upper gearbox.